6A01-T5铝合金型材及其焊接接头的疲劳极限测试

Analysis of the fatigue limits of the 6A01-T5 aluminum alloy profile and its welded joint

为了快速、准确地验证材料的疲劳极限,从试验方法和试样组的测试顺序两个方面进行分析研究。介绍了一种用3~5个试样验证疲劳极限的试验方法,并结合小样本的概率分析论证了该方法的有效性。利用这种试验方法,用简谐共振式高频疲劳试验机分别测试了取自6A01-T5铝合金型材的3种板试样,包括母材光滑试样、焊接平滑试样和焊接余高试样。结果表明,与传统应力升降法相比较,试验验证方法具有节省试样和缩短试验周期的优点。根据疲劳寿命影响因素和试样断口图片,分析了焊接接头疲劳性能测试用试样的差异,并推荐了平滑试样与余高试样的检测顺序,为铁路机车车辆构件疲劳性能检测提供了一种有效方法。

In order to quickly and accurately verify the fatigue limit of the 6A01-T5 aluminum alloy profile, the test method and the test order of specimen groups were analyzed respectively. A validation test method of fatigue limit, where fatigue limit could be assessed with 3 -5 specimens,was introduced and detailed analyzed on the basis of small-sampling proba- bility method. A high-frequency fatigue testing machine, which was in the harmonic resonance type,was used in this method to test three kinds of profile specimens of 6A01-T5 aluminum alloy. The three kinds are the smooth specimens with the base material, the welded joint spec- imens without removing reinforcement, and the welded joint specimens with removed rein- forcement. The experimental results show that the validation test method can save samples and shorten experimental periods in comparison with the traditional up-and-down method. Be- sides ,the difference between the two welded joint specimens for the fatigue test is analyzed according to the fracture pictures and impact factors on the fatigue life. The detection order of the two kinds of welded joint specimens, without removing reinforcement and with removed reinforcement, is recommend as well. The above-mentioned work provides the technique sup- port for the checking of fatigue proprieties of railway vehicle components.